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https://www.readbyqxmd.com/read/28934616/a-model-based-bayesian-solution-for-characterization-of-complex-damage-scenarios-in-aerospace-composite-structures
#1
H Reed, Cara A C Leckey, A Dick, G Harvey, J Dobson
Ultrasonic damage detection and characterization is commonly used in nondestructive evaluation (NDE) of aerospace composite components. In recent years there has been an increased development of guided wave based methods. In real materials and structures, these dispersive waves result in complicated behavior in the presence of complex damage scenarios. Model-based characterization methods utilize accurate three dimensional finite element models (FEMs) of guided wave interaction with realistic damage scenarios to aid in defect identification and classification...
September 5, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28931373/improving-contig-binning-of-metagenomic-data-using-formula-see-text-oligonucleotide-frequency-dissimilarity
#2
Ying Wang, Kun Wang, Yang Young Lu, Fengzhu Sun
BACKGROUND: Metagenomics sequencing provides deep insights into microbial communities. To investigate their taxonomic structure, binning assembled contigs into discrete clusters is critical. Many binning algorithms have been developed, but their performance is not always satisfactory, especially for complex microbial communities, calling for further development. RESULTS: According to previous studies, relative sequence compositions are similar across different regions of the same genome, but they differ between distinct genomes...
September 20, 2017: BMC Bioinformatics
https://www.readbyqxmd.com/read/28928413/allele-age-under-non-classical-assumptions-is-clarified-by-an-exact-computational-markov-chain-approach
#3
Bianca De Sanctis, Ivan Krukov, A P Jason de Koning
Determination of the age of an allele based on its population frequency is a well-studied problem in population genetics, for which a variety of approximations have been proposed. We present a new result that, surprisingly, allows the expectation and variance of allele age to be computed exactly (within machine precision) for any finite absorbing Markov chain model in a matter of seconds. This approach makes none of the classical assumptions (e.g., weak selection, reversibility, infinite sites), exploits modern sparse linear algebra techniques, integrates over all sample paths, and is rapidly computable for Wright-Fisher populations up to N e  = 100,000...
September 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28928409/modelling-sequences-and-temporal-networks-with-dynamic-community-structures
#4
Tiago P Peixoto, Martin Rosvall
In evolving complex systems such as air traffic and social organisations, collective effects emerge from their many components' dynamic interactions. While the dynamic interactions can be represented by temporal networks with nodes and links that change over time, they remain highly complex. It is therefore often necessary to use methods that extract the temporal networks' large-scale dynamic community structure. However, such methods are subject to overfitting or suffer from effects of arbitrary, a priori-imposed timescales, which should instead be extracted from data...
September 19, 2017: Nature Communications
https://www.readbyqxmd.com/read/28927844/reliability-modelling-of-redundant-safety-systems-without-automatic-diagnostics-incorporating-common-cause-failures-and-process-demand
#5
Siamak Alizadeh, Srinivas Sriramula
Redundant safety systems are commonly used in the process industry to respond to hazardous events. In redundant systems composed of identical units, Common Cause Failures (CCFs) can significantly influence system performance with regards to reliability and safety. However, their impact has been overlooked due to the inherent complexity of modelling common cause induced failures. This article develops a reliability model for a redundant safety system using Markov analysis approach. The proposed model incorporates process demands in conjunction with CCF for the first time and evaluates their impacts on the reliability quantification of safety systems without automatic diagnostics...
September 16, 2017: ISA Transactions
https://www.readbyqxmd.com/read/28923019/evolutionary-history-and-functional-divergence-of-the-cytochrome-p450-gene-superfamily-between-arabidopsis-thaliana-and-brassica-species-uncover-effects-of-whole-genome-and-tandem-duplications
#6
Jingyin Yu, Sadia Tehrim, Linhai Wang, Komivi Dossa, Xiurong Zhang, Tao Ke, Boshou Liao
BACKGROUND: The cytochrome P450 monooxygenase (P450) superfamily is involved in the biosynthesis of various primary and secondary metabolites. However, little is known about the effects of whole genome duplication (WGD) and tandem duplication (TD) events on the evolutionary history and functional divergence of P450s in Brassica after splitting from a common ancestor with Arabidopsis thaliana. RESULTS: Using Hidden Markov Model search and manual curation, we detected that Brassica species have nearly 1...
September 18, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28922786/relapse-free-survival-as-a-surrogate-for-overall-survival-in-the-evaluation-of-stage-ii-iii-melanoma-adjuvant-therapy
#7
Stefan Suciu, Alexander M M Eggermont, Paul Lorigan, John M Kirkwood, Svetomir N Markovic, Claus Garbe, David Cameron, Srividya Kotapati, Tai-Tsang Chen, Keith Wheatley, Natalie Ives, Gaetan de Schaetzen, Achmad Efendi, Marc Buyse
Background: We assessed whether relapse-free survival (RFS; time until recurrence/death) is a valid surrogate for overall survival (OS) among resected stage II-III melanoma patients through a meta-analysis of randomized controlled trials. Methods: Individual patient data (IPD) on RFS and OS were collected from 5826 patients enrolled in 11 randomized adjuvant trials comparing interferon (IFN) to observation. In addition, IPD from two studies comparing IFN and vaccination in 989 patients were included...
January 1, 2018: Journal of the National Cancer Institute
https://www.readbyqxmd.com/read/28922123/a-data-driven-approach-for-furniture-and-indoor-scene-colorization
#8
Jie Zhu, Yanwen Guo, Han Ma
We present a data-driven approach that colorizes 3D furniture models and indoor scenes by leveraging indoor images on the internet. Our approach is able to colorize the furniture automatically according to an example image. The core is to learn image-guided mesh segmentation to segment the model into different parts according to the imaged object. Given an indoor scene, the system supports colorization-by-example, and has the ability to recommend the colorization scheme that is consistent with a user-desired color theme...
September 18, 2017: IEEE Transactions on Visualization and Computer Graphics
https://www.readbyqxmd.com/read/28920986/stratification-in-binary-colloidal-polymer-films-experiment-and-simulations
#9
D K Makepeace, A Fortini, A Markov, P Locatelli, C Lindsay, S Moorhouse, R Lind, R P Sear, J L Keddie
When films are deposited from mixtures of colloidal particles of two different sizes, a diverse range of functional structures can result. One structure of particular interest is a stratified film in which the top surface layer has a composition different than in the interior. Here, we explore the conditions under which a stratified layer of small particles develops spontaneously in a colloidal film that is cast from a binary mixture of small and large polymer particles that are suspended in water. A recent model, which considers the cross-interaction between the large and small particles (Zhou et al...
September 18, 2017: Soft Matter
https://www.readbyqxmd.com/read/28920931/single-molecule-fret-reveals-the-energy-landscape-of-the-full-length-sam-i-riboswitch
#10
Christoph Manz, Andrei Yu Kobitski, Ayan Samanta, Bettina G Keller, Andres Jäschke, G Ulrich Nienhaus
S-adenosyl-L-methionine (SAM) ligand binding induces major structural changes in SAM-I riboswitches, through which gene expression is regulated via transcription termination. Little is known about the conformations and motions governing the function of the full-length Bacillus subtilis yitJ SAM-I riboswitch. Therefore, we have explored its conformational energy landscape as a function of Mg(2+) and SAM ligand concentrations using single-molecule Förster resonance energy transfer (smFRET) microscopy and hidden Markov modeling analysis...
September 18, 2017: Nature Chemical Biology
https://www.readbyqxmd.com/read/28916284/stereotactic-body-radiotherapy-versus-low-dose-rate-brachytherapy-for-localised-prostate-cancer-a-cost-utility-analysis
#11
J Helou, S Torres, H B Musunuru, J Raphael, P Cheung, D Vesprini, H T Chung, L D'Alimonte, M Krahn, G Morton, A Loblaw
AIMS: To conduct a cost-utility analysis comparing stereotactic body radiotherapy (SBRT) with low dose rate brachytherapy (LDR-BT) for localised prostate cancer (PCa). MATERIALS AND METHODS: A decision-analytic Markov model was developed from the healthcare payer perspective to simulate the history of a 66-year-old man with low-risk PCa. The model followed patients yearly over their remaining lifetimes. Health states included 'recurrence-free', 'biochemical recurrence' (BR), 'metastatic' and 'death'...
September 12, 2017: Clinical Oncology: a Journal of the Royal College of Radiologists
https://www.readbyqxmd.com/read/28916180/interpreting-temporal-fluctuations-in-resting-state-functional-connectivity-mri
#12
REVIEW
Raphaël Liégeois, Timothy O Laumann, Abraham Z Snyder, Juan Zhou, B T Thomas Yeo
Resting-state functional connectivity is a powerful tool for studying human functional brain networks. Temporal fluctuations in functional connectivity, i.e., dynamic functional connectivity (dFC), are thought to reflect dynamic changes in brain organization and non-stationary switching of discrete brain states. However, recent studies have suggested that dFC might be attributed to sampling variability of static FC. Despite this controversy, a detailed exposition of stationarity and statistical testing of dFC is lacking in the literature...
September 12, 2017: NeuroImage
https://www.readbyqxmd.com/read/28915795/future-complications-of-chronic-hepatitis-c-in-a-low-risk-area-projections-from-the-hepatitis-c-study-in-northern-norway
#13
H Kileng, L Bernfort, T Gutteberg, O S Moen, M G Kristiansen, E J Paulssen, L K Berg, J Florholmen, R Goll
BACKGROUND: Hepatitis C (HCV) infection causes an asymptomatic chronic hepatitis in most affected individuals, which often remains undetected until cirrhosis and cirrhosis-related complications occur. Screening of high-risk subjects in Northern Norway has revealed a relatively low prevalence in the general population (0.24%). Despite this, late complications of HCV infection are increasing. Our object was to estimate the future prevalence and complications of chronic HCV infection in the period 2013-2050 in a low-risk area...
September 16, 2017: BMC Infectious Diseases
https://www.readbyqxmd.com/read/28915754/modeling-the-mechanism-of-cln025-beta-hairpin-formation
#14
Keri A McKiernan, Brooke E Husic, Vijay S Pande
Beta-hairpins are substructures found in proteins that can lend insight into more complex systems. Furthermore, the folding of beta-hairpins is a valuable test case for benchmarking experimental and theoretical methods. Here, we simulate the folding of CLN025, a miniprotein with a beta-hairpin structure, at its experimental melting temperature using a range of state-of-the-art protein force fields. We construct Markov state models in order to examine the thermodynamics, kinetics, mechanism, and rate-determining step of folding...
September 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28915306/cost-utility-study-of-warfarin-genotyping-in-the-vachs-affiliated-anticoagulation-clinic-of-puerto-rico
#15
Carlos Martes-Martinez, Cristian Méndez-Sepúlveda, Joel Millán-Molina, Matthew French-Kim, Heriberto Marín-Centeno, Giselle C Rivera-Miranda, José J Hernández-Muñoz, Jorge Duconge-Soler
OBJECTIVE: To evaluate the cost-utility of the pharmacogenetic-guided dosing of warfarin (PGx), when compared to the current dosing strategy. METHODS: A Markov model was developed to assess the impact of the genotypingguided warfarin dosing in a hypothetical cohort of patients. The model was based on the percentage of time patients spent within the therapeutic international normalized ratio (INR) range (PTTR). PTTR estimates and genotype distribution were derived from a cohort of patients (n = 206) treated in the Veteran Affairs Caribbean Healthcare System (VACHS) and from results of other research study...
September 2017: Puerto Rico Health Sciences Journal
https://www.readbyqxmd.com/read/28910782/spectral-analysis-of-epidemic-thresholds-of-temporal-networks
#16
Yi-Qing Zhang, Xiang Li, Athanasios V Vasilakos
Many complex systems can be modeled as temporal networks with time-evolving connections. The influence of their characteristics on epidemic spreading is analyzed in a susceptible-infected-susceptible epidemic model illustrated by the discrete-time Markov chain approach. We develop the analytical epidemic thresholds in terms of the spectral radius of weighted adjacency matrix by averaging temporal networks, e.g., periodic, nonperiodic Markovian networks, and a special nonperiodic non-Markovian network (the link activation network) in time...
September 11, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28910764/efficient-message-passing-methods-with-fully-connected-models-for-early-vision
#17
Xiao Tan, Changming Sun, Fumin Shen, Kwan-Yee K Wong
Fully connected Markov random fields and conditional random fields have recently been shown to be advantageous in many early vision tasks being formulated as multi-labeling problems, such as stereo matching and image segmentation. The maximum posterior marginal (MPM) inference method in solving fully connected models uses a hybrid framework of mean-field (MF) method and a filtering like approach, and yields excellent results. In this paper, we extend this framework in several aspects. First, we provide an alternative inference method employing a fractional belief propagation based method instead of MF...
September 8, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28910342/home-modification-to-reduce-falls-at-a-health-district-level-modeling-health-gain-health-inequalities-and-health-costs
#18
Nick Wilson, Giorgi Kvizhinadze, Frank Pega, Nisha Nair, Tony Blakely
BACKGROUND: There is some evidence that home safety assessment and modification (HSAM) is effective in reducing falls in older people. But there are various knowledge gaps, including around cost-effectiveness and also the impacts at a health district-level. METHODS AND FINDINGS: A previously established Markov macro-simulation model built for the whole New Zealand (NZ) population (Pega et al 2016, Injury Prevention) was enhanced and adapted to a health district level...
2017: PloS One
https://www.readbyqxmd.com/read/28903559/three-faces-of-n-acetylaspartate-activator-substrate-and-inhibitor-of-human-aspartoacylase
#19
Maria G Khrenova, Ekaterina D Kots, Sergey D Varfolomeev, Sofya V Lushchekina, Alexander V Nemukhin
Hydrolysis of N-acetylaspartate (NAA), one of the most concentrated metabolites in brain, catalyzed by human aspartoacylase (hAsp) shows a remarkable dependence of the reaction rate on substrate concentration. At low NAA concentrations, sigmoidal shape of kinetic curve is observed, followed by typical rate growth of the enzyme-catalyzed reaction, whereas at high NAA concentrations self-inhibition takes place. We show that this rate dependence is consistent with a molecular model, in which N-acetylaspartate appears to have three faces in the enzyme reaction, acting as activator at low concentrations, substrate at moderate concentrations, and inhibitor at high concentrations...
September 13, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28903016/arthroscopic-meniscectomy-for-degenerative-meniscal-tears-reduces-knee-pain-but-is-not-cost-effective-in-a-routine-health-care-setting-a-multi-center-longitudinal-observational-study-using-data-from-the-osteoarthritis-initiative
#20
Jan J Rongen, Tim M Govers, Pieter Buma, Maroeska M Rovers, Gerjon Hannink
OBJECTIVES: It is disputed whether arthroscopic meniscectomy is an (cost-) effective treatment for degenerative meniscus tears in day-to-day clinical practice. The objective of this study was to assess the cost-effectiveness of arthroscopic meniscectomy in subjects with knee osteoarthritis, in routine clinical practice, while taking into account the increased risk for future knee replacement surgery. We compared cost-effectiveness of arthroscopic meniscectomy compared to no surgery. DESIGN: - We used a state transition (Markov) simulation model to evaluate the cost-effectiveness of arthroscopic meniscectomy compared to no surgery in subjects with knee osteoarthritis (age range 45- 79 years)...
September 10, 2017: Osteoarthritis and Cartilage
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